<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script src="http://localhost:8080/static/js/app.js"></script>
  <img src="http://localhost:8080">
  <input type="text" value="张三">
  <button id="btn">发送</button>
  <a href="">
    fdssd
  </a>
  <span id="xss">坤哥
  </span>
  <script>
    let str = 'i'
    var btn = document.getElementById('btn');
    var input = document.getElementsByTagName('input')[0];
    btn.onclick = function () {
      var xss = document.getElementById('xss');
      let a = document.querySelector('a')
      xss[str + 'nner' + 'HTML'] = input.value
    }
  </script>

</body>

</html>